This invention relates to a forwardly-directed rotary baler for forming swathed hay or straw material into cylindrical bales, and in particular to a rotary baler of the type which rolls the material along the ground as the bale is being formed. The baler may be a separate unit which is mountable on the front of a wheeled power unit to form a self-propelled assembly, or the baler may be integral with the power means, thereby providing a self-propelled unit. This type of machine is termed a ground-rolling forwardly-directed rotary baler.
In general, the commercially successful rotary balers pick up the swath material and introduce it into a hollow cylindrical chamber defined by a system of moving belts. The belts extend around and enclose almost the entire circumference of the forming bale. They expand against applied tension as the bale is growing in size and presses outwardly against them. The belts act to move and guide the material along an arcuate path, thereby forming it into a cylindrical bale. The circumferential speed of the belts is greater than the ground speed of the baler--thus the bale is continually spun at a relatively high rate with a view to increasing its density. This type of machine is termed herein a full circumference belt baler.
These prior art balers are characterized by a number of problems. For example, they are pull type units--that is, they are pulled by a power unit, such as a tractor--as a result, the operator has a poor view of the swath being worked on. The relatively rapid spinning of the forming bale tends to cause undesirable leaf loss and shattering damage to the hay or straw material. Since the tractor precedes the baler, and since it is necessary for the tractor to move on and off the swath as it is maneuvered (to feed the swath onto the bale in a manner which produces a bale of constant diameter), there is considerable leaf shatter arising from the grinding action of the tractor wheels. Most of this shattered leaf material, which has a valuable protein content, is not incorporated in the bale. The machines are characterized by having narrow inlets for the incoming swath material--such inlets commonly involve a pair of compressing rolls; the narrowness of these inlets influences the thickness of the swath that can be accommodated, thereby slowing the rate of advance of the machine and thus its baling rate. The bale, being completely enclosed in belts, is not easily accessible in the event that the operator should need to clear piled-up material from the bale-forming zone. The machines which are available do not have a fully automatic twine wrapping and cutting mechanism which the operator can use without stopping the machine and manually engaging in succession the wrapping and cutting mechanisms. Because the entire weight of the bale is carried by the baler, the latter's construction must be particularly strong. For this reason and the need for the extensive driven belt system, the available machines are mechanically complicated and therefore are expensive to buy and operate, as well as being somewhat hazardous to use.
There has also been proposed in the prior art the combination of the concepts of forwardly directing the baler (to enable the operator to see the swath stretching before him) and ground rolling the bale during its formation (to reduce the complexity and extent of the belt system and thus the cost of the baler). This is, for example, shown in U.S. Pat. No. 3,815,344, issued to Kucera. However, up until now, no such unit has been developed which confines the front lower circumferential surface of the bale being formed. Thus there is undesirable spilling, piling up and skidding of the hay or straw through this gap. To my knowledge, no one has heretofore provided a ground-rolling forwardly-directed rotary baler having sufficiently complete circumferential enclosure of the growing bale so as to eliminate the spilling problem and thereby duplicate the mechanical control over the bale which is inherent in the commercially successful full circumference belt balers.